Endless bands for technical applications of various kinds are in daily use, for instance in power transfer, e.g., transmissions, for transport purposes, as tools in the form of grinding belts, as measurement auxiliaries, as well as in data storage devices. Also known is their use for ink storage in the form of ink ribbons for typewriters and printers.
Endless bands are often utilized in such a way that only one of the two available surfaces is used for the desired purpose, e.g., for transport, or storage, such that only one surface is exposed to wear. According to A.F. Moebius (1790-1868), an endless strip may be produced by connecting the narrow edges of a given plane strip in such a way that the initially diagonally opposite corners are made to coincide. The resulting Moebius strip represents a surface having one side only; one can reach any point of that surface, or use it for any technical purpose, without going beyond the strip's edge. Moebius strips, in the form of ink ribbons utilizing both sides of the starting ribbon are used in modern typewriters and heavy-duty printers (impact printers). These ribbons and ribbon cartridges must be produced in large quantities at the lowest costs possible. An indispensable precondition for this is a high degree of automatization.
A short amortization period for the production facilities and high versatility have become possible only through the application of robots. Their accurate positioning behavior, the possibility of simple programming and of self-control (monitoring) has also proved advantageous in the manufacturing of ink ribbons and ink ribbon cartridges. In case of changes in the geometry of the ribbon cartridge and the material quality of the ribbons, the flexibility of automated assembly installations using such robots allows the required parameters to be easily modified.
While the assembly of ink ribbons has been at least partly effected manually, here too, transfer lines have recently been applied, both of the linear type and as rotary-table installations, in which in particular the threading into a ribbon cartridge of the ribbon is performed robotically. With Moebius ribbons, however, manually performed intermediate steps are necessary, causing the output rate of the installation to be considerably reduced and the defect rate, being dependent on the reliability of the operator, to be relatively high.
It is thus an object of the invention to produce, by improvement of per se known assembly robots, a Moebius ribbon and to automate the process, while giving full consideration to the fact that the ribbons being used are usually mechanically sensitive, and that along their full, endless and two-sided extent, these ribbons must guarantee a high and constant quality printout.
A further object of the invention is the development of an assembly apparatus and methodology having lowered manufacturing and operational costs, the warranty of high versatility, as well as the possibility of easily adapting the working parameters such as speed and forces to differing ribbon qualities and ribbon cartridge geometries.